Constructing High-Performance ZIF-8-Modified PVA/Poly(ionic liquid) Composite Membranes with Integrated Dyes/Cu ²⁺ Adsorption and Antibacterial Properties

The efficient removal of harmful dyes, metal ions, and bacteria from wastewater remains challenging due to their high chemical stability and low affinity for many conventional adsorbents. In this work, a high-performance composite membrane was constructed by incorporating zeolitic imidazolate framework-8 (ZIF-8) into a poly(vinyl alcohol)/poly(ionic liquid) (PVA/PIL) matrix. This strategic design, incorporating both PIL and ZIF-8, aims to achieve efficient adsorption and antibacterial action. As a result, the PVA/PIL/ZIF-8 composite membrane exhibits remarkable adsorption capacities of 684.47 and 68.89 mg/g for MO and Cu²⁺, respectively. The primary adsorption mechanisms were attributed to electrostatic interactions and ion exchange. Furthermore, the composite membrane exhibited excellent antimicrobial activity, achieving a 100% antibacterial rate against common Gram-positive/-negative bacteria. This antibacterial mechanism, which combines electrostatic interaction, membrane permeability, and ZIF-8-mediated oxidative stress, endows the PVA/PIL/ZIF-8 membrane with potent and sustained antibacterial activity. This study provides a promising strategy for developing multifunctional membrane materials capable of simultaneously removing dyes, metal ions, and bacteria from industrial wastewater.